import fetch from 'dva/fetch';
import {getLocalStorage} from '../utils/storagehelper';
import {message} from 'antd';

const codeMessage = {
  200: '服务器成功返回请求的数据',
  201: '新建或修改数据成功。',
  202: '一个请求已经进入后台排队（异步任务）',
  204: '删除数据成功。',
  400: '发出的请求有错误，服务器没有进行新建或修改数据的操作。',
  401: '用户没有权限（令牌、用户名、密码错误）。',
  403: '用户得到授权，但是访问是被禁止的。',
  404: '发出的请求针对的是不存在的记录，服务器没有进行操作',
  406: '请求的格式不可得。',
  410: '请求的资源被永久删除，且不会再得到的。',
  422: '当创建一个对象时，发生一个验证错误。',
  500: '服务器发生错误，请检查服务器',
  502: '网关错误',
  503: '服务不可用，服务器暂时过载或维护',
  504: '网关超时',
};

function checkStatus(response) {
  if (response.status >= 200 && response.status < 300) {
    return response;
  }

  const errorName = `request error ${response.status}: ${response.url}`;
  const errortext = codeMessage[response.status] || response.statusText;

  const error = new Error(errortext);
  error.name = errorName;
  error.response = response;
  throw error;
}

function json(response) {
  return response.json();
}

function checkCode(json) {
  if (json.code === undefined) {
    message.error('json format error');
    return json;		// just return it is
  }

  switch (json.code) {
    case 0:
      break;
    case 1:
      message.error(json.message);
      break;
    default:
      message.error('unknown error');
      break;
  }
  return json;
}

/**
 * Requests a URL, returning a promise.
 *
 * @param  {string} url       The URL we want to request
 * @param  {object} [options] The options we want to pass to "fetch"
 * @return {object}           An object containing either "data" or "err"
 */
export default function request(url, options) {
  const newOptions = {
    ...options,
    credentials: 'include',
  };
  const token = getLocalStorage('current_user') ? getLocalStorage('current_user').token : null;

  if (newOptions.method === 'POST' || newOptions.method === 'PUT') {
    newOptions.headers = {
      Accept: 'application/json',
      'Content-Type': 'application/json; charset=utf-8',
      ...newOptions.headers,
      'Authorization': token,
    };
    newOptions.body = JSON.stringify(newOptions.body);
  } else {
    newOptions.headers = {
      Accept: 'application/json',
      'Content-Type': 'application/json; charset=utf-8',
      ...newOptions.headers,
      'Authorization': token,
    };
  }

  return fetch(url, newOptions)
    .then(checkStatus)
    .then(json)
    .then(checkCode);
}
